Panel examines digester innovation

About 35 percent of waste sent to landfills is organic. If that waste was used for energy instead, the equivalent of 20 percent of U.S. coal plant emissions would be eliminated.

John McDowell, regional sales manager for Eisenmann Corp., pointed out that fact during International Biomass Conference & Expo breakout panel “Innovation in Digester Design and Utilization.” McDowell explained the benefits of integrating anaerobic digestion into urban farming operations, highlighting a Chicago project the company is providing technology to.

Titled The Plant, the non-profit project will be a zero-energy, urban vertical farming operation and is located in a refurbished meat packing facility. As products are produced at The Plant, waste will be sent to the anaerobic digestion system, closing the energy loop. It will produce 2 million Btu per hour of biogas, 200 kilowatts of electricity, press cake for composting and a liquid soil amendment.

Not all substrates are equal, McDowell said, as different amounts of biogas are produced with different amounts of different feedstocks. “Depending on what’s available, we can help develop a recipe to optimize economics of the project,” he said. “That can lead to what technology we select for the AD process.”

For The Plant, Eisenmann has chosen its high solids, horizontal flow plug system, which can accept a wide range of feedstocks without a need to slurry substrates, and is a fully-automated, continuous system.

McDowell said permits are currently being finalized for The Plant, and construction is planned for June 2012. “We expect to bring the system online in January 2013,” he said.

Other speakers on the panel with McDowell included Paige Griffin, graduate research assistant at Colorado State University; Greg Karr, program manager at MRIGlobal; and James Rosenblum, environmental health science doctoral candidate at Ohio State University.

For more information about The Plant, read Biomass Power & Thermal article Brewing Up Biomass.